Thermostatic circuit closer



Wmv 13 9 M3923a THERMOSTATIC CIRCUIT CLOSER Filati A'Lg. 21 1922Patented Nov. 13, 1923.

PATENT OFFICE.

IYICCORIVIIXCKl C. MPHERSON, OF HAMMOND, INDIANA.

THRMOSTATIC CIRCUIT CLOSER.

Application filed August 12, 1922. Serial No. 581,448.

To all 'whom t may coa-cem.:

Bel it known that MCCORMACK C. Mo- PI-rnnsoN, citizen of the UnitedStates, residincr at Hammond, in the `county of Lake and @tate ofIndiana,'has invented certain new and' useful 'Improvements inThermostati'c Circuit Closers, of which the following is aspecification.

.The present invention relates to frost alarms adaptedA particularly forgiving warning of a dropping in temperature in orchards, and the like,where a freezing or low temperature isv harmful andrundesirable. V Y Anobject Aof the present invention is to provide' a device which isthermostatically controlled to close a circuit when thetem` perature isreduced to a predetermined degree, or thereabouts, for the purpose, of

2Q operating a bell, a horn, or any 'suitable electrically controlledmechanism, for tale' mg action when such low temperature is attained. AY y Various devices of this character have at `a predetermined lowtemperature so that they cannot be tampered with or changed as to thetime of'operation;l which cannot be easily broken; which comprises butfewV parts so assembled as toproduce a device whichmay be suspended orplaced ina desired'location where it may-be'susceptible to slightVvariations ,in temperature and unfailingly operate when thetemperaturefalls to a predetermined degree.

A still further objectof the invention is toprovide a frost alarm ofthischaracter which has but one movable part and a pair of contacts,` themovable part` and contacts being all sealed and enclosedfifn such mannerthatl accessthereto cannot-fbehad, and conhereto.

heretofore been patented and commerciallyv parts housed, sealed andfixed for operation sequently the fixed relation or adjustment of theseparts cannot be accidentally or willfully changed.

With the foregoing and other `objects in view theinvention will be morefully described hereinafter, and will be more particularly pointed outin the claims appended In the drawings, wherein like symbols refer tolike or corresponding parts throughout theseveral views.' l A.

Figure 1 is a perspective view of a frost alarm constructed accordingtothe present invention and in one position of use.

Figure 2 is a face view of the device.

[Figure 3 is a vertical cross section through the device takensubstantially on the line 3-3 of Figure 2. 'Y

Figure 4 is a detail perspective view Vshowing a portion of thethermometer tube with one of the contacts blown therein, the sectionbeing taken substantially on the line 4 4 of Figure 2.

In the drawings, 10 designates a panel board of any suitable size andconfiguration for supporting and housing the various parts of thedevice, the panel board being shown as of rectangular oblongconstruction in the present instance.

yA thermometer vtube 11, having at its lower end the usual bulb 12 and'provided at its upper end with a second bulb 13, is

mounted on the' panel board 10 and is adapted to extend upwardly at asufficient inclination to the horizontal toobtain the desired action andat the same time to position the tube 11 substantially longitudi@ tionand the bulb 12 constitutes the lower termination of the tube. lThe tube11 is held in the groove 14 by straps 15 which engage across the outerside of the tube and which are screwed or otherwise suitably secured tothe panel board 10 to hold the ther'inom'- eter tube 11 irn'ily in itsseat in the panel board. Such construct-ion prevents vibration of thetube so that when the panel board receives jars, falls to the ground,and the like there is little likelihood of the tube 11 becoming damaged.

The bulb 1Q is protected by a plate which is secured across the lowerend oi the groove 1st and over the bulbi 1Q to ward otl impact ofsurrounding object with the bulb and thus prevent accidental breakage ofthe same. The plate 12 is preferably slotted or otherwise perforated toadmit 'tree access o t air to the bulb 1Q.

The body portion of the tube 11 also protected and housed by means of asheath plate or protector 17 which is et sutleient width to overlap thegroove 11 and Awhich is laterally enlarged opposite ends to receiveattaching screws 18, or the like. for securing the plate i7 to the taceot the panel board 10 and enclose the tube 11. The body portion of thetube 11 may be thus completely enclosed `lfrom view and trom access byexternal objects tor the complete protection oit the tube because thepresent dovice not adapted Yjor adjustment or Yfor taking readings, andthe parts thereo't are so arranged that thcj.Y cannot be tamj'ieredWit-h and easily broken; thus producing a practical tool proof devicewhich cannot easily get out ot' order.

The tube 11 is adapted to contain a rela tively short column of mecury19, or other suitable electric conducting substance which is arrangedintermediately of the body portion of the tube 11 and supported in thetube at opposite ends by columns 2() and 21 ot' the creosote or alcohol,or other suitably electricity non-conducting substance Which is readilysusceptible to expansion and contraction under the influe-nee oftemperature changes.

Blown or otherwise suitably positioned in the tube 11 are fixed contacts22 and 23 which project into the cavity of the tube in rthe path ofmovement of the column of mercury 19, and which are spaced aipart adistance which permits Asimultaneous contact with the mercury only whenthe latter is permitted to move down in the tube 1l to the desiredextent. These contacts 22 and 23 are so lo ated that when a temperatureof approximately 34; degrees is reaclied the column of mercury 19bridges the contacts, and thus closes any electrical circuit in Whichthe contacts may be included. It will be noted that the contacts extend'trom an inner side of the tube 11, and constitute terminals of wires 24Which are seated in grooves 25 formed in the rear tace of the panelboard 10. The ivires 24 are secured to the inner ends of binding posts526 which project through the ,forward tace ot the panel board 10, attheir inner ends but which are seated in suitable recesses 2T at theinner side ot' the panel board. The grooves and recesses 27 at the innerside ot the panel board may be closed and by suitable covering` or layer28 Which is cemented or otherwise secured in position to prei/'entaccess to the parts so that such parte cannot be easily bro-ken ordisconnected. The outer ends of the binding posts i6 provide terminalsfor electric Wires 29 which lead from a source of electrical energy andto any suit-able mechanism as may be de'red when a loiv temperatureapproaching the freezing point is reached.

The device is particularly adapted 'l'or use in orchards to protect thetrees and fruit from injury from frost, and the device is adapted to besuspended or otherwise placed in an exposed position so that When cold`Winds or air strike the device it will respond, close the electriccirc-uit and thus operate as desired to protect the fruit.

The panel board 10 may be equipped with a hanger 30 ofany suitableconstruct-nm., and shown in the present instance as in the form o'l aplate with an inverted key hold slot 31 therein through which a headednail or the like may be engaged Jfor holding the panel board upon apost, tree, 'tence or the like7 and the plate 30 may be connected to thepanel board by a pivot 32 permitting the swinging oit the plate 30downwardly against the rear side of the board out of the Way forconvenience in storing and shipping.

It obvious that various changes and modificationsmay be made in thedetails ol construction and design ot the above specifically -describedembodiment ol this invention Without departing from the spirit thereof,such changes and modilications being restricted only by the scope o'lthe lollowing claims.

lVhat is claimed is:

A thermostatic circuit closer comprising a. panel board having anupwardly inclined groove in its outer face extending in a generalhorizontal direction, a thermometer tube seated in the groovesubstantially flush with the outer face of the panel board and with itsbulb in the lower end thereof, protecting means secured to the outer'tace ot' the panel board over the bulb and the tube for housing thesame, lixed contacts blown into the lower side of the tube and.projecting into the adjacent Wall of the groove ot the panel board, a.non-conducting column of liquid in the lower end ot said tube, a columnot mercury arranged in the tube, above said non-conducting liquid forbridging said contacts when a predetermined low temperature reached,said panel board having channels `therein leading downwardly from saidcontacts, Wires extending from the contacts downwardly through saidchannels, to Ipermit connection of the wires to the blinding postsmounted on the outer face of binding posts, and 'a covering platesecured the panel board and terminating lat their `over the rear face ofsaid panel board for 1 inner ends in the lower ends of said chanhou-singin the wires and `the inner ends of 5 nels and Connected to said wires,the lower the binding posts.

end portions of said channels opening In testimony whereof I ax mysignature.

through the rear face of the panel board MCCORMACK C. MCPHERSON.

